(1) Field of the Invention
This invention generally relates to the field commonly known as crop dusting, more particularly known as aerial application of fertilizers, fungicides, pesticides or other substances affecting the yield of a crop. However, the present invention need not be limited to aircraft such as airplanes or helicopters; aerial distribution may be considered distribution by any vehicle that disperses a substance over desired substratum via air rather than essentially directly upon the substratum. More specifically, the invention disclosed herein relates to a system for controlling the distributions of at least two different substances, independently of each other.
The invention is essentially an improvement to existing aerial application (crop dusting) systems for the delivery of chemical(s) or other substance(s) to fields. Traditionally, aerial applications by airplanes or helicopters utilize a tubular boom underneath the primary wing or rotor, supporting a row of first nozzles or other valves governing release of fertilizer, fungicide, pesticide or another substance transported within the boom; for the sake of convenience, such substances will be referred to merely as a substance, which may include one or more solitary substance(s) as well as combination(s) and/or mixture(s) of the same, in whatever form that is capable of such combination(s) and/or mixture(s) (primarily liquid or solid). The desired concentration of first substance is typically supplied from a first tank on board the aircraft, then pressure-pumped through the boom and out of the first nozzles as the aircraft flies over the desired field. When more than one substance is desired to be distributed over the same field, the aircraft traditionally had to spray the field two or more times using the same first set of nozzles.
The improved system disclosed herein applies two separate substances, independent in amount (or rate of distribution) and/or application pattern (or timing of distribution), in one pass over the field, using two essentially independent subsystems of tanks, pumps and nozzles. This system can project a second substance into the airstream flow of a first substance, while the first substance is being released from a nearby first nozzle of the first subsystem. The invention disclosed herein will also allow a second substance (that may not be legally mixed with a first substance within the same tank) to essentially be mixed in the air outside the aircraft, and applied at a rate and pattern separate from the first substance, according to the desired chemical distribution prescription for the field.
Although the present invention has a number of embodiments, it essentially comprises a means of transporting a second substance to a second set of dispersion nozzles, separate from the transport and dispersal of a first substance. The invention may also include a means of independently maintaining the constancy of dispersion of the second substance, despite any variation in dispersion of the first substance. Alternatively, the invention may include a means of independently controlling variation of dispersion of the second substance, despite any variation in dispersion of the first substance.
(2) Description of Related Art Including Information Disclosed Pursuant to 37 CFR 1.97 and 1.98. Modern aerial application of agricultural substances requires precision in the geographic positioning and piloting of the aircraft, and control of the system used to distribute the substance(s). Such precision agriculture practices therefore require various technologies that allow agricultural personnel to use information management tools to optimize agriculture production. These technologies allow aerial application pilots to improve application accuracy and efficiency, which saves time and money for the farmer and the pilot. Several types of precision agriculture technologies include global positioning systems (GPS), geographic information systems (GIS), soil sampling, yield monitoring, nutrient management field mapping, aerial photography, variable rate technology, and pulse width modulation.
Variable rate technology facilitates distribution of a desired amount of crop production substance in a variable pattern or amount on a field; variable rate technology is used in agricultural operations such as fertilizer application, seeding and chemical applications. Variable application rates typically change according to a preset map, or through information gathered by sensors. Major advantages of using variable rate technology include conservation of fuel, and minimizing excessive spraying of chemical on crops; both advantages save farmers money.
A global positioning system provides the location information to enable the variable rate equipment to adjust the flow rate for different sections of the field. GPS operates through a system of satellites, computers and receivers that is able to determine the latitude and longitude of a receiver on earth, by calculating the time difference for signals from different satellites to reach the receive. GPS enables agricultural pilots to more easily track the acres that have been sprayed, track the spray application rate and log the data.
Another modern technology for aerial application is a geographic information system, which is essentially a computer based collection of information that can be displayed in the form of maps. GIS provides lots of useful information such as field borders, soil types, buildings, pesticide-sensitive areas and pest populations, all of which can be displayed using interactive maps. GPS and GIS can be integrated, allowing a pilot to successfully maneuver while efficiently spraying a field using variable rate equipment.
Pulse width modulation allows independent control of nozzle flow rate and operating pressure during an application. This means flow rate can be adjusted to maintain a desired amount of gallons per acre (of fluid substances), without significantly changing droplet size. Alternatively, droplet size can be changed to reduce drift while not affecting the flow rate (gallons per acre).
There are many aerial distribution systems that distribute chemicals and other substances at a fixed rate and steady pattern, which are standard on crop dusting airplanes and helicopters. More recently, there have appeared aerial distribution systems that distribute a substance at variable rates and/or variable distribution patterns on a particular target area. These systems typically utilize onboard computers and GPS transceivers to receive relevant data and coordinate the release of substance on the target area. The following is a representative example of such a known system. (For the sake of convenience and clarity, to distinguish elements that may appear separately in two systems (also known as subsystems), the element of the first subsystem may include a “first” in its identification whereas the element of the second subsystem may include a “second” in its identification.)
As a prelude to going airborne to apply chemicals or other substances, the owner of the target field (or the pilot or other agricultural personnel) often collects relevant information such as IR imagery, yield data, grid samples, the amount of substance to be applied to the target field, the geographical coordinates of the target field and the location of portions of the target field to receive more (or less) of the substance, and the current wind speed and direction. Some of that information is saved in a format for recognition by a computer, such as (for example) on a field-specific “prescription card” in machine readable language. The onboard computer may also be programmed to govern a variable flow control valve, and the computer also receives flight-in-progress data such as the location of the target area and the aircraft, the ground speed and direction of the aircraft, and the volume of the first substance passing downstream of the flow control valve.
The first tank is filled with the first substance through the infill end of the first infill line, often located at a midpoint along the aircraft fuselage. The first infill line often extends forward to fill the first tank (often in front of cockpit). Often with the assistance of a pump, the first substance exits the bottom of the first tank (often underneath the front nose of the aircraft), through a relatively large pipeline that is often opened and closed via mechanical linkage, often from a cockpit lever operated by the pilot. The pilot typically pushes the lever forward (upon approach to the target field) to open the spray valve within the pipeline, to ready the system for allowing the computer to commence distribution of the substance as directed by the prescription. (Pulling the lever aft closes the spray valve, causing the substance to return to the tank; this usually occurs as the aircraft is leaving the target field, or in the event it becomes necessary to manually override the automated distribution of substance.)
The first substance flows aft through the pipeline to a flow control valve (such as, for example, the IntelHow® control valve marketed by Del Norte Technology, Inc.); the flow control valve has sensors that allows the onboard computer to essentially compare the volume of the first substance that has already passed aft versus the volume of the first substance prescribed at that time by the prescription card, then determine whether that amount that actually passed through satisfies the prescribed amount (given the aforementioned aircraft and field data). Depending upon that comparison, the flow control valve does one of the following: (a) permits all of the first substance to flow through the downstream flowline into a distribution channel such as a hollow boom; (b) partially blocks the downstream flowline, allowing only some of the first substance to flow through the downstream flowline to the boom; or (c) totally blocks the downstream flowline, preventing any of the first substance from flowing through the downstream flowline to the boom.
A first duct, off of the downstream flowline, diverts a sample of the first substance to a first pressure meter, which determines whether there exists the threshold pressure needed for starting the distribution of the first substance through the first nozzles spaced periodically along the hollow boom affixed beneath the aircraft wing or rotor. The boom fills with the first substance and, when the boom pressure of first substance exceeds the nozzle release threshold, the first substance sprays out of the first nozzles in a spraystream.
Once the pilot positions the aircraft to approach the target area at an acceptable altitude and speed, and opens the pipeline spray valve using the cockpit lever, the computer controls the amount (rate) and pattern (timing) of the first substance released from the first nozzles and thereby applied to the target area, until the pilot closes the pipeline upon leaving the target area.
The pilot then re-positions the aircraft to spray another swath of the field with the first substance. To the extent desired (especially as directed by the prescription card), the computer may vary the amount and/or pattern of the first substance released in each swath.
For first substances that are powdered or granulated, the boom and first nozzles may be replaced by a bin and an exit grate having gates; traditionally the pilot controlled the timing and amount of gate opening and closing using a hand lever (with a stop) similar to that used to control the fluid application system. More recently, gate control may be automated and computerized, such as (for example) with the system manufactured by Houma Avionics, Inc. under the name AutoCal. Such automatic gate controllers may be interfaced with and governed by an onboard computer such as that previously described.
Some systems have patents. Known in the art are the following, arguably related to the patentability of the present invention:
U.S. Pat. No.1st InventorDate of Patent3,933,309OdegaardJan. 20, 19763,994,437KittermanNov. 30, 19764,055,303BrownOct. 25, 19774,703,891JacksonNov. 3, 19875,915,377CoffeeJun. 29, 19995,915,377CarltonNov. 2, 19995,003,782KimDec. 21, 19996,871,796JonesMar. 29, 2005
U.S. Pat. No. 3,933,309 issued to Odegaard appears to disclose a spray boom including separate internal compartments, each having a row of nozzles running the length of the underside of the boom; each compartment receives respective spray material through an infeed port in the compartment wall adjacent a respective feeder tank. The nozzles for each compartment have ball valves that are spring-biased closed, opening when air pressure in the compartment exceeds the spring biasing. There is a common air pump that pressurizes the feeder tanks, which have piping running through control valves en route to the respective compartments. When the pilot opens a control valve, pressurized spray material in a feeder tank flows into the respective compartment, under pressure in excess of the air pressure existing in the compartment; when it exceeds the spring biasing, the ball valve opens and allows the material to spray out of the nozzle.
The Odegaard patent discloses that it is intended to provide a spray boom with “improved control over the rate of discharge of the spray material so that the same or different materials can be applied at selectively different rates.” (Column 1, lines 43-47.) It also discloses that it is intended to provide a spray boom “which is capable of having the spray pattern selectively varied while in flight to maximize the efficiency and effectiveness of distribution of the material to be sprayed and to provide better control of the patterns so that material will not be sprayed on areas it should not be sprayed”. (Column 2, lines 3-9.) However, the Odegaard patent discloses that the “controls for admitting material to compartments . . . form no part of this invention, nor does the means for controlling the pressure within the compartments to control the opening and closing of the ball valves”. (Column 4, lines 47-51.) Shortly thereafter, this patent discloses that the “controls may be such that each compartment has the same or a different rate of discharge”. (Column 4, line 62-63) Later, the Odegaard patent discloses that the “separate compartments also permit the use of different types of nozzles which can discharge at different rates or provide a different character of discharge therefrom, such as in the size of the droplets”. (Column 5, lines 15-17.) At one place, this patent discloses that the nozzles can have special arrangements to “accomplish some special result, such as overlapping strips of sprayed materials”. (Column 5, lines 21-22.) More often however, this patent indicates that the rows of nozzles are staggered so that “material discharged from the openings of one compartment fall on an area not covered by the material discharged from the openings of the second compartment.” (Column 6, lines 35-38.)
Notably, the Odegaard patent does not disclose a second substance dispersal system having a second (independent) charging pump, and a second set of nozzles serviced by essentially separate conduits for almost instantaneous precision discharging. Neither does this patent disclose a GPS receiver, or computer hardware and software converting the wind speed and the aircraft's speed, altitude and direction, to accomplish dispersion of different substances in accordance with a predetermined dispersion prescription for a particular field. Moreover, although the Odegaard patent mentions separate dispersal systems allowing simultaneous dispersion of two different chemicals, one at a constant rate and the other at a different variable rate and/or pattern of dispersion, this patent does not disclose anything enabling anybody to accomplish those ultimate results.
U.S. Pat. No. 6,871,796 issued to Jones et al. discloses a spray boom including a liquid supply conduit having a row of nozzles, the conduit being rotatable around a longitudinal axis to vary the angulation of the nozzles; there is also a flow shut-off valve approximately midway along the conduit, allowing the pilot to stop the supply of liquid spray material to the conduit nozzles nearest the wingtips. This patent also discloses use of a “ground positioning system”, and a computer program that performs such functions as selecting a desired nozzle performance, determining the nozzle angle required for achieving that performance at a measured wind speed, adjusting the nozzle angle, and actuating the flow shut-off valve in response to deviation from the predetermined flight path.
The Jones patent does not disclose a second chemical dispersal system that is separate and independent from the first chemical dispersal system, having a second chemical reservoir, independent charging pump, and set of nozzles serviced by essentially separate conduits for almost instantaneous precision discharging. And except for nozzle angulation, this patent does not disclose computer hardware and software converting the wind speed to accomplish dispersion of the chemicals in accordance with a predetermined dispersion prescription for a particular field.